Previous techniques have been devised for plugging electric and other conduits to prevent gases and other types of harmful substances from contaminating the conduits and posing a threat to serviced structures. One such technique involves the use of expandable foaming agents which are injected into a conduit, foamed to fill a plug, and hardened in situ. Foaming systems conventionally have more than one component which are mixed just prior to placement in conduit.
It is known practice to mix the components in a flexible container and then squeeze the container to extrude its contents through a container outlet into a conduit in which a sponge or other barrier element has already been positioned. After this has been done, another barrier element is inserted in a conduit to provide a confined space within which the foaming and foam hardening action can take place.
This procedure can be messy as well as ineffectual. It is often difficult to work within the confined space of a conduit and waste can occur. Perhaps more importantly, improper or inadequate placement of a foaming agent may take place and a fluid-tight plug may not be formed.